Coating metals with zinc



42 sheets-auen 1.

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H. ROBERTS. l Coating' Metals with Zinc.

1 Patented May il?, |881.-

WTIJES 55S 2 sheets-augen 2,

` (No Model.)

H. ROBERTS Coating MetalswwithZino,

Pa1ein1ed1v1'ay 17,1881.

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N. PETERS, Phoilrulhagrnphur, Wllhlngun. D. C

UNITE-n STATESy PATENT @Ferca l COATING 1META LS /WITH ZINC.

.SPECIFICATION forming part `of 4Letters `Patent No. 241,721, datedMay 1.7, .1881.

Application (iledJanuary 27, 1881." (No model.)

To allwhom it may concern.- Be it known that I, HENRY ROBERTS, a citi# zen of the United States, residing at J ohns town, Cambria county, inthe State ot Penn- Sylvania, have invented certain new and useful Improvements relating to Coating Metals" that any metal capable ot' being coated with zinc or analogous metal may be substituted,

`and that the wires may be flat, round, or of various other sections, and that they may be known as wires, or by the Various other technical names, as hoop-iron, bale-ties, or the like.

I provide a long bath of melted zinc with the heating-fires around the exterior, and the bottom relatively cool, for the subsidence of what is known as (lross. I provide the ordinary surface-coating of sal-ammoniac, and

the ordinary im mersing-sinker, beneath which the wires are passed through the bath in order to insure their long and uniform immersion.

I provide peculiarly-efficient means for wiping off the surplus metal and for insuring a succession of fresh surfaces of the wiping material. I attain this end by leading the wires in an inclined direction upward from the bath through a mass of suitable wiping material, which is constantly moved in a direction opposite to that of the wires.` The wiping being effected in this manner and immediately on the emergence of the wires from the melted bath, I can reduce the consumption of zinc to a minimum and insure that it is left with more than ordinary uniformity of thickness.

' I have also improved the wiping by the application of a material hitherto unused for the purpose. It is what is Aknown as mineral wool,7 slag wool,77 or silicate cotton a silky fibrous matter produced by the treatment of cinder from a blast-furnace by blowing it with acurrent of steam athigh pressure.` It is i highlyelastic and soft, is not destroyed by the heat, has a just sufficient property of adhesion j to the melted metal or wiping-power and is sufticientlymobileinits nature to allow of being these for each wire.

worked by rollers, so as to be moved in the manner I-` desire. l will, for brevity, term this peculiar material slag wool.

I employ two or more pairs ot' rolls, one be hindthe other,fto complete 'the wiping. The wires emerge from the wiping smoothly and uniformly coated, and are ready to he wound on reels for transportation and-usel The preparation of the surfaceto receive the melted zinc and the treatment `inthe bath of zinc maybe of the ordinary an d long approved character.

The accompanyingdrawings form a part ot' this specilication, and represent what I consider the best means ot' carrying out'the invention. I

Figure lis avertical section through the entire apparatus. Fig. 2 is a plan view ot' the same. The remaining li gures represent details detached. Fig. 3 is a central vertical sectioin ot' my improved wiping-box. Fig. 4 is a plan view of a portion ofthe same, showing the ends of the agitating-rolls, their operatin g-gear, au(A the partition-space at the side. t

Similarletters of reference indicate like parts in all the figures.

` Ithave shown but one wire.

A is the reel from which the wire `m is de' livered; B, the acid-bath; C, a quan ti ty of broken stone therein; D, a series of rolls, some ot' which are preferably `turned by-power to aid the movement of the wire; E, a guiding sheave; F, tubes through the drying-furnace G, and H a series of guiding-sheaves, from which the Wire is plunged directly into the bathI ot' melted metal.

J J are sinkers in the melted metal, so

`placed that the wires in passing under these end an outwardly-projecting lug, which is just the right size to engage in graduated holes in a bridge or piece spanning the endot' the tank.

0n emerging from the metal bath I, the wires are led up through slots in the bottom ot' Aa partially overhanging box, K, which contains aliberal supply ofthe slag wool k, which serves `as the `wiping material, and should be kept Each has at its upper ICO io jections l, which engage with a just sufficient quantity of the slag wool, and drag it along in the direction opposite to the movement of the wires m.

The rollers are turned slowly, only about one revolution in two seconds. They agitate the slag wool, and continually present new surfaces thereof to the steadily-moving wires.

The general tendency of the rollers is to move the wiping material gradually from the back to the front of thc wiping-box; or, in other words, toward that sideot` the wiping-box which overhangs the tank. The slag wool is in its nature a good non-conductor. Its temperature is soon raised by the workin g so thatit approximates closely to that of the melted zinc, except that the upper stratum is kept wet and relatively cool by sprinkling with water, either ordinary fresh water or preferably a solution of tungstate of soda. The melted zinc removed by the particles of slag wool and moved actively toward the receiving side of the box is deposited in that edge of the box and dropped through the openings there provided into the tank. The affinity or adhesion of the melted metal to the earthy wool is very slight.

Instead of accumulating and becoming densely compacted in the receiving side of the wiping-box, I take measures to produce a circulation of the material. It is worked under and over the several rollers. Each roller of each pair carries the slag wool toward the tank on that side where it eifects the wiping and away from it on the side where it is returning idly.

P is an additional roll, of which I can use eral mode of operation,in so far as it is agitated k to present continually new surfaces and is t moved in a direction contraryto the motion of the wires, are made the subjects of separate applications for patents. So, also, the peculiarities of the acid-bath and drying-furnace form the subject of a separate application for fpatent.

more than one, if necessary; but my experiments do not indicate such need to aid in transferring the fibrous material from that end of the box toward the back or more distant side ofthe box. The result is a constant agitation of the wiping material and a presentation of fresh surfaces to the melted metal coating on the wire; also a movement of the material between the rolls toward the receiving side of the box, and thence upward and backward to the other side,from whence it is again moved forward. I believe that the lowermost rollers of each pair also carry a liberal current ofthe slag wool downward land move it backward in the base of the box; but of this I have not so well assured myself.

The action of the rolls not only presents fresh surfaces and presents them with a motion opposite to that of the wires, so as to insure an effective wiping, but also tends to induce a quite compact condition of the fibrous material at the base of the receiving side of the wipingbox. It tends the better to express any particles of melted metal which have beenbrought with it from the other portions of the box. I esteem this a marked advantage.

The journals of the several rollers L l are of considerable length and project through the walls,which I provide in each end of the wipingbox with an air-space between. This facilitates access for examination and oiling, and tends to prevent the induction of heat.

The lower part, K2, of the side of the wipingbox nearest tothe tank of melted metal is made in a separate piece from the rest, and can be removed on taking out the screws 7c', which are inserted through lugs in the upper portion, K, of the side. the finely-broken wiping material which tends to accumulate there. f

Modifications may be iliade in the forms aud proportions of the details. I have worked successfully with the wiping-box only about two (2) feet wide, so as to give a wiping traverse of only two (2) feet; but this may be varied. I believe that little gain would result from an increase of the wiping traverse, because wires of small size become rapidly cooled. For very large wires a wider wiping-box would be expedient.

There is a tendency of the slag wool to become worn, abraded, or broken, so as to accumulate a fine dust in the bottom. When this has become too ine I replace it with fresh. N o particular difficulty is experienced if considerable of the broken earthy matter falls upon the melted zinc. i

The dotted circles represent the gearing by which the rolls L are turned. I have not deemed it necessary to represent the belt through which the motion is received. l mount the gears in two independent trains, in order that I can, if preferred, after the operation has fairly commenced, arrest themotion of the rods which are farthest from the metal bath am. operate the remainder.

The wiping materia-l employed and the genl claim as my invention- The two trains of rollers L l with their operating-gears, iu combination with the top carrying-roll, P, wiping-box K, wiping material 7c, and a vessel for containing coating metal, as herein specified.

In testimony whereof I have hereunto set my hand, at New York city, N. Y., this 19th day of January, 1880, in the presence of two subscribing witnesses.

HENRY ROBERTS.

Witnesses:

CHARLES C. STE'rsoN, M. F. BoYLE.

This facilitates the removal of IOS 

